Transfer mechanism



Feb. 10, 1942.

Filed Feb. 12, 1941 3 Sheets-Sheet' '1' INVENTORS RICHARD L.W|LCOX ERETBR 50w ATI'ORNEY Feb.10,'1942. R. L. WILCOX E 2,272,592

TRANSFER MECHANISM INVENTORS RICHARD L. WILCOX ATTORNEY Feb. 10, 1942.R. L. WILCOX ETAL 2,272,592

TRANSFER MECHANISM Filed Feb. 12, 1941 3 Sheets-Sheet 5 INVENTOR5RICHARD LWILCOX BY HERBERT LHOYT ATTORNEY Patented Feb. 10, 1942TRANSFER MECHANISM Richard Lester Wilcox and Herbert L. Hoyt, Wa-

terbury, Conn, assignors to The Waterbury Farrel Foundry and MachineCompany, Waterbury, Conn, a corporation of Connecticut ApplicationFebruary 12, 1941, Serial No. 378,596

40 Claims.

This invention relates to transfer mechanism for metal working machineryor the like. It is particularly adapted for use with a header orupsetting machine or the like, having a plurality of dies.

A principal object of this invention is to provide a transfer mechanismthat will operate efficiently at such speed as to make possible anincrease of the speed of the machine with which it is associated andthereby increase its output, this being in part accomplished byminimizing the number and extent of the moving parts and their operativerelation with each other; and further, to so arrange the mechanism thatthe workpiece to be transferred will be quickly and securely gripped andWill be quickly released through the action of positively actuatedelements as distinguished from the conventional type of fingers thatspring over the workpiece and held it entirely by spring tension, suchfingers acting without tendency to misalign the workpiece. This, andother objects of the invention are obtained by providing an oscillatingcarrier, upon which finger tongs have independent relative movement andare positively actuated to grip and retain the workpiece during transferand release at a predetermined station, which grip may be made variablein the extent of its pressure upon the workpiece.

Another object accomplished by this invention is to provide for arelative timing of the action of the tong fingers so that the operationof grasping or releasing the blank may be varied at either station or ata point therebetween and such operation accomplished with either anaccelerated or a retarded speed.

Other objects of this invention, and its construction and operation,will appear from the following description and accompanying drawings.

A preferred embodiment of the invention is disclosed in the drawings,but other forms and embodiments may be adopted to obtain the purposesand Objects of this invention equally as well as the one herein shown.

In the accompanying drawings, wherein like numerals of referenceindicate like parts in the several figures;

Figure 1 is a transverse sectional view of a header, upsetting machineor the like, with this improved transfer mechanism associatedtherewith;

Figure 2 is a fragmentary plan view thereof;

Figure 3 is a detailed sectional view, the parts (C1. Ill-12) in sectionbeing taken generally upon line 3-3 of Figure 2;

Figure 4 is a fragmentary plan view of the oscillating member andassociated parts, the

5 parts in section being taken generally upon line 44 of Figure 3;

Figures 5 and 6 are detailed views of the tong slide, tongs andassociated parts; and

Figure '7 is a view of the tong mechanism 10 shown at the lower part ofFigure 3 but on an enlarged scale.

Referring to the drawings; the numeral I0 designates a header frame,upsetting machine, or the like; II a shaft journaled therein; and

I2 and I3 cams fixed thereto.

Journaled upon the stud I4 are the levers I5 and I6. Theformer has a camroll I! in contact with the cam I2 and the latter a cam roll I8 incontact with the cam I3.

Secured in the frame II], in any preferred manner, is a die block I9,shown herein as having three dies therein, severally designated as 20,2| and 22, the first being a cut-oif die, and the other two are workingdies. The workpiece is ejected from the die by a knockout pin 83 movedin one direction by a knockout rod 84 suitably mounted in the frame III.This die block, the means for holding the same in the frame, the diesthemselves, and the knockout mechanism, constitute no part of thispresent invention.

Secured to the frame, and bridging an opening therein in front of thedie block, is a bracket 23, having mounted therein the rock shafts 25and 26. Fixed on the shaft 25 is a segment gear 21, to which ispivotally connected the yoke 28.

A yoke 29 is connected with the lever I5, and between which and the yoke28 is a connection rod 30, around which, in part, is a spring 3| betweenthe collars 32. This rod 30 is threaded into the yoke 28, and by reasonof the nuts thereon, its length may bevaried in a Well known manner.

Rotation of the cam I2 imparts to the segment gear 2! an oscillatingmovement through the lever I5 and connection rod 30. A coil spring 33between a fixed part and the lever I5 holds the cam roll IT. in contactwith the cam I2. A similar spring 82 performs the same function for thelever I6, cam roll I8 and cam I3.

The shaft 26 is oscillated from the lever I6 I5 and threaded in the yoke29, provides for a radial variation of the position of the stud 39. Byreason thereof the length of the arc, through which the teeth of thesegment gear 27 travel, is subject to variation and adjustment,

Journaled in the bracket 23 is a crank shaft 40, having a pinion 4|thereon, the teeth of which mesh into those of the segment gear 21.

Upon the crank cheek of the shaft 40 is a stop arm 42, and fixed thereinis a crank pin 43. The extent of rotation of the crank shaft isdetermined by the contact of the stop arm 42 with the lugs 44 upon thelower end of the stop plates 45. These stop plates are adjustablymovable in the bracket 23 by means of the adjusting screws 46 in a wellknown manner and are positioned upon opposite sides of the center of theshaft 45 and substantially equally distant therefrom.

The compensating spring 3| accommodates the movement of the segment gear2'! as the limit of movement of the crank shaft is determined by thestop arms 42 and stop lugs 44.

Adjustably mounted on the face of bracket 23 is a plate 41 having anintermeshing tongue 48 and groove connection therewith, a screw 49providing for relative movement of the plate.

Adjustably mounted on the face of plate 4i is a bearing plate 50, havinga tongue and groove connection therewith. Relative movement of thebearing plate 50 upon the plate 4! is obtained by the action of theadjustment screw 53. Both the plates 4! and 50 are secured rigidly tothe bracket 23 by the screws 52 which pass through holes sufficientlyenlarged to provide for the maximum movement of the plates. By thisadjustment of the plates both a vertical and a horizontal adjustment onthe bracket 23 is obtained, and in their adjusted positions both aresecured against movement by the screws 52.

The numeral 54 designates a swivel or rockable head. A shaft 55 thereonis journaled in the plate 50. On this swivel head is a slide block 19,within which a transfer slide 55 is movable and held againstdisengagement therefrom by the cap 8|. The screws 80 secure both the cap8| to the slide block and the latter to the swivel head. The transferslide 56 is reciprocated through rotation of the crank shaft 40, and anoscillating movement is imparted to the swivel head 54. The extent ofthis oscillating movement is variably determined by the engagement ofthe stop arm 42 and lugs 44 in the manner above described.

In the swivel head 54 is a tong slide 58, having thereon two blocks 59and 60 spaced from each other, the latter having a pointed end withconverging cam faces 6|. This slide acquires a reciprocatory motionwithin the swivel head 54 through the rock lever 62 fixed on the shaft25, and having a ball end 63 in the open space be tween the blocks 59and 60, and in engagement with both, substantially as shown in Figure 5.Slide 58 has an independent movement in the swivel head 54 derived fromthe cam i3, lever l5, rod 34, rock lever 35, shaft 26 and rock arm 62.In the transfer slide 56 is a pin 64, which carries the tongs,comprising in part tong jaws 65, to which are secured the grippingfingers 56, recessed or otherwise formed at their lower ends toaccommodate a workpiece 5'! engaged thereby. While the fingers 65 areherein shown as secured to the tong jaws, obviously they may be integralif desired. These tongs operate in much the same manner as a pair ofordinary shears. The rear end of the tong jaws is upon that side of thepin 64 opposite the finger 66 thereon. In

the tail of each of these tong jaws is a stud 68 carrying a cam roll 69.As the slide 58 moves endwise in the swivel head toward the tongs, thecam faces 5| are projected between the cam rolls 53 (Fig. 6) andseparate the fingers 66. The tong jaws and the fingers 66 are moved totheir closed positions by a wire spring 10 or the like, which encirclesthe hub of the tongs and bears against the pin 1|, fixed in the tongtails. To provide a long bearing for the jaws one tong is journaled forsubstantially its entire length upon the pin 64 and the other tong isjournaled upon the hub of the first tong (Fig, 3). Thus both tongs areprovided with relatively long bearings. The tongs and the coil spring 10are held against axial movement on the pin 54 by a washer 12 secured tothe pin by a screw 13 or the like. The proper relative position of thefingers is determined by the set screws 15 which abut against a stud 14when the fingers 66 are closed. Each tong jaw has a lug 16 which limitsthe extent of the opening of the fingers 66 by its engagement with astop face 11 upon the other tong jaw.

On the swivel head 54 is a fixed plate 18 that is engaged by the end ofthe roll studs 58 to prevent the fingers 66 from moving toward the faceof the dies to cause binding as a workpiece is pushed through thefingers 66 into the heading dies.

As the rod 34 is threaded into both yokes 35 and 31 means are thusprovided to change the distance between the levers I6 and 36 and therebyvary the relative position of the slide 58.

In operation the fingers 66 close onto a workpiece 61 as it is beingejected from the first die (2|). This is accomplished by timing the cam|3 so that the slide 58 is raised and with it the cam plate 60, thuswithdrawing the cam faces 6| either in whole or in part from between thecam rolls 69, allowing the tong fingers 66, through the coil spring 10,to close onto the workpiece. Then, through the timing of cam 2, the tongjaws, with the workpiece in the fingers 66, are oscillated from theposition wherein the workpiece is in register with the first die to aposition wherein the workpiece is in register with the opening in thesecond die (22) with the fingers 65 still in their closed position,substantially as shown by broken lines in Figure 1. As the punch carriedby the gate advances and pushes the workpiece out of the fingers 66 andinto the second die, the beveled cam faces 6| are projected between thecam rolls 69. The tong jaws are thus separated and the fingers 66 openin time to clear the advancing punch which will in part pass between theopen fingers while the crank shaft 40 is at rest. The fingers are closedby the spring I0, but this closing is controlled by the positivelyactuated cam mechanism, which predetermines both the time and extent ofsuch closing. This results from the fact that the rolls 69 are incontact with the cam faces 6|, and the extent of the closing of thefingers depends upon the extent of withdrawal of the cam. In Figure 6the fingers are illustrated as fully opened. As the cam is withdrawn thefingers close gradually as the rolls 69, under the action of the coilspring 70, ride against the cam faces 5|, until the cam is entirelywithdrawn. Thus the extent of movement of the cam and the timing thereofcontrols both the extent and time of closing of the fingers. The onlyparts that require quick operation are those connected with the openingof the fingers. These are relatively light parts. Therefore, the timingfor the return oscillation of the fingers 66 to the first die is greatlylengthened, as during the return of fingers 66 they are in their openposition (Fig. 6) until about to receive another workpiece as it isejected from the first die. It is possible, therefore, for the punchcooperating with the first die to be at its extreme forward positionadjacent to the face of the die or just beginning to return, at the timethe fingers, then open, will straddle the punch and be in a position toclose immediately the punch starts to return. Thus it is possible totransfer very short work as well as long work within the range of themachine.

The foregoing description is directed solely toward the constructionillustrated, and it is to be understood that the privilege of resortingto all mechanical changes to which the device is suitable is reserved,the invention being defined and limited only by the scope of theappended claims.

What is claimed is:

1. In a transfer mechanism; an oscillating member for transferring aworkpiece from one station to another; tongs pivotally mounted betweenthe ends thereof about a common center and carried by the oscillatingmember; and means associated with the oscillating member movabletherewith and relatively thereto, that enter the space between the tailportions of the tongs and separate the tongs.

2. In a transfer mechanism, plural working tools; an oscillating membermovable about a center between said tools; tongs carried thereby fortransferring a workpiece from one tool to another tool; and meansindependently and positively movable in opposite directions upon theoscillating member for separating the tongs.

3. In a mechanism for transferring a workpiece from one station toanother; an oscillating member; a reciprocating member slidable on theoscillating member; tongs pivotally mounted on the reciprocating memberabout a common center; and means on the reciprocating member movableinto and out of engagement with the tongs for separating the grippingends thereof.

4. In a transfer mechanism; an oscillating member for transferring aworkpiece from one station to another; tongs carried thereby; re-

ciprocating means carried by the oscillating member for separating thetongs; and a rock member journaled in a fixed part and operativelyconnected with said reciprocating means for imparting positive movementthereto in opposite directions.

5. In a transfer mechanism; a rockable head member; a carrying memberthereon; tongs movably mounted upon the carrying member; means formoving the carrying member relatively to the head member and therebyactuating the head member; and independent means for actuating thetongs.

6. In a transfer mechanism; a rockable head member; a reciprocatingcarrying member thereon; tongs movably mounted upon the carrying member;means to reciprocate the carrying member relatively to the head memberand thereby actuating the head member; and independent means foractuating the tongs.

7. In a transfer mechanism; a rockable head member; a carrying memberslidable thereon; tongs movably mounted upon the carrying member; crankactuated means for moving the carrying member relatively to the headmember; and independent means for actuating the tongs.

8. In a transfer mechanism; a head member; a carrying member thereon;tongs pivotally mounted upon the carrying member; means for moving thecarrying member relatively to the head member and whereby the latter iscaused to oscillate; a cam member movable with the carrying member;independent means for moving the cam member relatively to the carryinmember and thereby separating said tongs.

9. In a transfer mechanism; a rockable head member; a carrying member onand having a reciprocatory movement in respect to the head member; tongspivotally mounted upon the carrying member; a cam member on and having areciprocatory movement in respect to the head member; and independentmeans for positively moving the cam member into and out of the path ofthe tongs and whereby the tongs will be positively separated by the cammember when traveling in one direction.

10. In a transfer mechanism; arockable head member; a carrying member onand having a reciprocatory movement in respect to the head member; tongspivotally mounted upon the carrying member; a cam member on and having areciprocatory movement in respect to the head member; and independentmeans for positively moving the cam member into and out of the path ofthe tongs and whereby the tongs will be separated when the cam member ismoved in one direction; and other means for closing the tongs when thecam member is moved in the other direction.

11. In a transfer mechanism; a rockable head member; a carrying memberon and having a reciprocatory movement in respect to the head member;tongs pivotally mounted upon the car rying member; a cam member on andhaving a reciprocatory movement in respect to the head member andindependent means for positively moving the cam member into and out ofthe path of the tongs and whereby the tongs will be separated when thecam member is moved in one direction; and spring means acting directlyon the tongs for closing the tongs when the cam member is moved in theother direction.

12. In a transfer mechanism; a rockable head member; a reciprocatingcarrying member thereon; tongs movable mounted upon the carrying member;a rock member for moving the carrying member relatively to the headmember and actuating the head member; adjustable stop members forlimiting the movement of the rock member; and independent means foractuating the tongs.

13. In a transfer mechanism; a rockable head member; a carrying memberthereon; tongs movably mounted upon the carrying member; means formoving the carrying member relatively to the head member; independentmeans for actuating the tongs; and means to variably time the means foractuating the tongs relative to the means for varying the movement ofthe carrying member.

14. In a transfer mechanism; a head member; a carrying member thereon;tongs movably mounted upon the carrying member that cross each other atthe point of support; means for moving the carrying member relatively tothe head member; and independent means for actuating the tongs that isprojected between the tail ends thereof and thereby separates thegripping ends thereof.

15. In a transfer mechanism; a rockable head member; a carrying memberthereon; tongs movably mounted upon the carrying member; means formoving the carrying member relatively to the head member and to actuatethe head member; independent cam means for separating the tongs; andstop means to predetermine the relative position of the tongs andthereby predetermining the relative position of the tongs with respectto the carrying member.

16. In a transfer mechanism; a rockable head member; a reciprocatingmember thereon and operably associated therewith; tongs movably mountedupon the reciprocating member; a gear actuated rock member; an operativeconnection between the reciprocating member and rock member wherebymovement is transmitted to the latter from the former and also to thehead member to actuate it; and means for actuating the tongs.

17. In combination with a header, upsetting machine or the like; a dieblock; plural dies in the die block; a bracket secured to the header radjacent to the die block; and oscillating mechanism on the bracket fortransferring a workpiece from one die to another die, consisting in partof a head member and a slide mounted to reciprocate on the head member;tongs carried by the slide; tong separating means on the slide movabletherewith and thereon for separating the tongs; and means operativelymounted in said bracket and having connection with the tong separatingmeans for actuating the same, said oscillating mechanism, tongs and tongseparating means being mounted on the bracket and assembled with theheader, upsetting machine or the like, as a unit.

18. In a transfer mechanism; a movable part; a pair of tong jaws mountedto rotate about a common center upon the movable part, said tong jawscrossing each other at said common center and having parts upon oppositesides thereof; a second movable part; and means upon the second movablepart for engaging and moving between that portion of the tong jaws uponone side of said common center, and thereby separating the gripping endsof said tong jaws.

19. In mechanism for transferring a workpiece from one station toanother station, comprising in part plural plates adjustable relativelyto each other; an oscillating member on one of the plates; a carriermember movable on the oscillating member; pivotally mounted tongs on thecarrier member; and an independently actuated tong separating member onthe carrying member.

20. In mechanism of the character described; a fixed plate; a carriermember movable opposite the face thereof; pivotally mounted tong jaws onthe carrier member, each having a part thereon which moves adjacent tothe fixed plate and holds the tong jaws against movement parallel withthe axis of their pivot mountings.

21. In a transfer mechanism; a carrier member; a stud carried thereby; apair of tong jaws pivotally connected therewith, each tong jaw having ahub thereon, the hub of one tong jaw being journaled on said stud andproviding a journal on which the hub of the other tong jaw is journaled.

22. In a transfer mechanism; a carrier memher; a stud carried thereby; apair of tong jaws pivotally connected therewith, each tong jaw having ahub thereon, the hub of one tong jaw being journaled on said stud andproviding a journal on which the hub of the other tong jaw is journaled;a resilient member centered about said stud, the opposite ends of whichapply pressure to the tail ends of the tong jaws to move the grippingends thereof toward each other.

23. In a transfer mechanism; a carrier membar; a stud carried thereby; apair of tong jaws pivotally connected therewith, each tong jaw having ahub thereon, the hub of one tong jaw being joumaled on said stud andproviding a journal on which the hub of the other tong jaw is journaled;a member fixed in the carrier member between the tong jaws; and anadjustable member on each tong jaw which abuts against the fixed memberand whereby one position of the tong jaws relative to the carrier membermay be determined.

24. In mechanism having fabricating dies, a transfer mechanism forcarrying a workpiece from one die to another die, comprising in part acarrier member, a pair of tong jaws pivotally mounted thereon, anindependent member projected between the tail portions of the tong jaws,

whereby the gripping ends of the tong jaws are moved away from eachother; a plate spaced from the tong jaws, and means to prevent rockingof the tong jaws upon their mounting as a workpiece is being projectedtherebetween from a fabricating die, comprising a member connected withthe tong jaws that travels in contact with said plate during themovement of the carrier member.

25. In mechanism for transferring a workpiece from one station toanother, having pivotally mounted gripping jaws, with tail portions uponone side of the pivot mounting, to hold a workpiece during transit; andpositive means projected into the open space between the said tailportions that limits the extent of the opening of the gripping jaws whilbeween the tail portions.

26. In mechanism for transferring a workpiece from one station toanother, having gripping jaws to hold a workpiece during transit; andmeans for moving the gripping jaws as a unit at variable speeds duringthe travel thereof from one station to another.

27. In a work transfer mechanism; a reciprocable first member; a secondmember journaled on a stationary part and adapted to be rocked by thefirst member when the first member is reciprocated; a pair of tongspivotally mounted on the first member; a third member on the secondmember and slidable relatively to the first member to move the grippingends of the tong jaws, both said first member and third member beingmounted and movable substantially parallel with each other and adjacentto the head portion of the second member; and means upon a fixed partseparately actuated to impart movement to the third member.

28. In a work transfer mechanism; a reciprocable first member; a secondmember journaled on a stationary part and adapted to be rocked by thefirst member when the first member is reciprocated; a pair of tongspivotally mounted on the first member; a third member on the secondmember and slidable relative to the first member to separate thegripping ends of the tong jaws, both said first member and third memberbeing mounted and movable substantially parallel with each other andadjacent to the head portion of the second member; and means upon afixed part separately actuated to impart movement to the third member,said means comprising in part a rock shaft journaled out of the path ofmovement of the said members; and means for imparting movement to therock shaft.

29. In a work transfer mechanism in accordance with claim 28 havingcompanion rock arms, one being fixed on the rock shaft, an adjustableconnection between the rock arms, and a cam for actuating the rock arms.

30. In a work transfer mechanism in accordance with claim 28, havingmeans for varying the extent of movement of the rock shaft and wherebyth extent of the movement of the third member is determined.

31. In a work transfer mechanism in accordance with claim 28, havingmeans for varying the extent of the relative timing of the rock shaft,and whereby the extent and timing of the third member in relation to thetong jaws is determined.

32. In a work transfer mechanism; a bracket; a plate adjustably mountedthereon; a bearing plate adjustably mounted upon said plate; a headmember journaled in the bearing plate; a slid block fixed to the headmember; a transfer slide movable in the slide block; a shaft having acrank thereon which is connected with the transfer slide, and whereby areciprocatory movement is imparted to the transfer slide and anoscillating movement to the head member; tong jaws pivotally mounted onthe transfer slide, the tail ends of the tong jaws being spaced fromeach other and the opposite ends adapted to grip a workpiece; a camslide movably mounted in th head member having a cam portion, positionedto be moved into and out of the open space between the tail ends of thetong jaws; and independently operated means positioned laterally to thhead member for moving the cam slide and projecting the cam thereon inbetween the tail ends of the tong jaws.

33. In a work transfer mechanism; a reciprocable first member; a secondmember journaled on a stationary part and adapted to be rocked therebywhen the first member is reciprocated; means to impart rec-iprocatorymovement to the first member, comprising in part a shaft, a crank on theshaft, a pinion on th shaft, a segment gear, the teeth of which meshinto those of the pinion; a rock member for moving the segment gearabout its axis; and an adjustable connection between the rock member andsegment gear, whereby the extent of movement of the latter may be variedand thereby vary the length of reciprocation of the first member; tongjaws mounted upon the first member; and a third member on the secondmember and slidable relatively thereto to separate the gripping ends ofthe tong jaws.

34. In a work transfer mechanism; a lengthwise reeiprocable firstmember; a second member journaled on a stationary part at a pointbetween the ends of the first member and adapted to be rocked therebywhen the first member is reciprocated; tong jaws pivoted on and carriedby the first member; a third member movably mounted on the second memberand slidable relatively to the first member to move the gripping ends ofsaid tong jaws away from each other; ad-

' justable means to limit the extent of movement of the gripping ends ofthe tong jaws; and means on a fixed part and separately actuated toimpart a sliding movement to the third member.

35. In a work transfer mechanism; a lengthwise reciprocable firstmember; means to reciprocate the first member; adjustable means to varythe extent of such reciprocation; a rockable second member journaled ona stationary part at a point between the ends of the first member andadapted to be rocked thereby when the first member is reciprocated; tongjaws pivoted on and carried by the first member; a third member on thesecond member and slidable relatively to the first member to move thegripping ends of the tong jaws away from each other; adjustable means tolimit the extent of movement of the gripping ends of the tong jaws;means on a fixed part and separately actuated to impart a slidingmovement to the third member; and adjustable means acting on the thirdmember to vary the extent of movement of the third member.

36. In a work transfer mechanism; a cooperating pair of tong jawsoperable about a common center and adapted to engage a workpiece betweenthe opposing ends thereof at one side of the common center, each tongjaw having a portion extending beyond the common center to its otherside; spring means to bias the tong jaws relatively to each other in onedirection; and means movable toward and away from said common center, tobe disposed between the extended portions of the tong jaws, to move thetong jaws relative y to each other in the other direction.

37. In a work transfer mechanism, in accordance with claim 36, havingmeans to pivot the tong jaws and the jaw moving means for simultaneousrocking movement, and common means to reciprocate the tong jaws and tosimultaneously rock the tong jaws and the tong jaw moving means aboutsaid pivot means.

38. In mechanism for transferring a workpiece from one station toanother; a carrying member; movably mounted gripping jaws thereon tohold a workpiece during transit; positive means engaging the jaws toopen the same; and resilient means for closing the jaws, the extent ofclosing and timing thereof being controlled in part by said positivemeans.

39. ,In a transfer mechanism; a carrying member; tongs mounted upon thecarrying member; yielding means for closing the tongs; and tong engagingmeans, movably mounted on the carrying members for opening the tongs,that in part control the closing of the tongs under the tension of thyielding means.

40. In a transfer mechanism; a carrying member; tongs pivotally mountedupon the carrying member; a cam member on the carrying member; means formoving the cam member on the carrying member into and out of the path ofthe tongs and whereby the tongs will be separated when the cam member ismoved in one direction; and other means for closing the tongs when thecam member is moved in the opposite direction, the closing of the tongsbeing in part controlled by the cam member.

RICHARD LESTER WILCOX. HERBERT L. HOY'I'.

